[PATCH v4 2/6] cfgfile: add support for global properties section

[Allain Legacy <allain.legacy@windriver.com>]

The current implementation of the cfgfile library requires that all
key=value pairs be within [SECTION] definitions.  The ini file standard
allows for key=value pairs in an unnamed section.

   https://en.wikipedia.org/wiki/INI_file#Global_properties

This commit adds the capability of parsing key=value pairs from such an
unnamed section. The CFG_FLAG_GLOBAL_SECTION flag must be passed to the
rte_cfgfile_load() API to enable this functionality.  Any key=value pairs
found before the first section can be accessed in the section named
"GLOBAL".

Signed-off-by: Allain Legacy <allain.legacy@windriver.com>
---
 lib/librte_cfgfile/rte_cfgfile.c | 16 ++++++++++++++++
 lib/librte_cfgfile/rte_cfgfile.h | 13 ++++++++++++-
 test/test/test_cfgfile.c         | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/lib/librte_cfgfile/rte_cfgfile.c b/lib/librte_cfgfile/rte_cfgfile.c
index 829109a77..832fea829 100644
--- a/lib/librte_cfgfile/rte_cfgfile.c
+++ b/lib/librte_cfgfile/rte_cfgfile.c
@@ -107,6 +107,22 @@ rte_cfgfile_load(const char *filename, int flags)
 
 	memset(cfg->sections, 0, sizeof(cfg->sections[0]) * allocated_sections);
 
+	if (flags & CFG_FLAG_GLOBAL_SECTION) {
+		curr_section = 0;
+		allocated_entries = CFG_ALLOC_ENTRY_BATCH;
+		cfg->sections[curr_section] = malloc(
+			sizeof(*cfg->sections[0]) +
+			sizeof(cfg->sections[0]->entries[0]) *
+			allocated_entries);
+		if (cfg->sections[curr_section] == NULL) {
+			printf("Error - no memory for global section\n");
+			goto error1;
+		}
+
+		snprintf(cfg->sections[curr_section]->name,
+				 sizeof(cfg->sections[0]->name), "GLOBAL");
+	}
+
 	while (fgets(buffer, sizeof(buffer), f) != NULL) {
 		char *pos = NULL;
 		size_t len = strnlen(buffer, sizeof(buffer));
diff --git a/lib/librte_cfgfile/rte_cfgfile.h b/lib/librte_cfgfile/rte_cfgfile.h
index b40e6a135..2dadd75d4 100644
--- a/lib/librte_cfgfile/rte_cfgfile.h
+++ b/lib/librte_cfgfile/rte_cfgfile.h
@@ -66,13 +66,24 @@ struct rte_cfgfile_entry {
 	char value[CFG_VALUE_LEN]; /**< Value */
 };
 
+/**@{ cfgfile load operation flags */
+enum {
+	/**
+	 * Indicates that the file supports key value entries before the first
+	 * defined section.  These entries can be accessed in the "GLOBAL"
+	 * section.
+	 */
+	CFG_FLAG_GLOBAL_SECTION = 1,
+};
+/**@} */
+
 /**
 * Open config file
 *
 * @param filename
 *   Config file name
 * @param flags
-*   Config file flags, Reserved for future use. Must be set to 0.
+*   Config file flags
 * @return
 *   Handle to configuration file on success, NULL otherwise
 */
diff --git a/test/test/test_cfgfile.c b/test/test/test_cfgfile.c
index faca89696..a7de3706c 100644
--- a/test/test/test_cfgfile.c
+++ b/test/test/test_cfgfile.c
@@ -163,6 +163,36 @@ test_cfgfile_missing_section(void)
 }
 
 static int
+test_cfgfile_global_properties(void)
+{
+	struct rte_cfgfile *cfgfile;
+	const char *value;
+	int ret;
+
+	cfgfile = rte_cfgfile_load(CFG_FILES_ETC "/missing_section.ini",
+				   CFG_FLAG_GLOBAL_SECTION);
+	TEST_ASSERT_NOT_NULL(cfgfile, "Failed to load config file");
+
+	ret = rte_cfgfile_num_sections(cfgfile, NULL, 0);
+	TEST_ASSERT(ret == 1, "Unexpected number of sections: %d", ret);
+
+	ret = rte_cfgfile_has_section(cfgfile, "GLOBAL");
+	TEST_ASSERT(ret, "global section missing");
+
+	ret = rte_cfgfile_section_num_entries(cfgfile, "GLOBAL");
+	TEST_ASSERT(ret == 1, "GLOBAL unexpected number of entries: %d", ret);
+
+	value = rte_cfgfile_get_entry(cfgfile, "GLOBAL", "key");
+	TEST_ASSERT(strcmp("value", value) == 0,
+		    "key unexpected value: %s", value);
+
+	ret = rte_cfgfile_close(cfgfile);
+	TEST_ASSERT_SUCCESS(ret, "Failed to close cfgfile");
+
+	return 0;
+}
+
+static int
 test_cfgfile_empty_file(void)
 {
 	struct rte_cfgfile *cfgfile;
@@ -198,6 +228,9 @@ test_cfgfile(void)
 	if (test_cfgfile_missing_section())
 		return -1;
 
+	if (test_cfgfile_global_properties())
+		return -1;
+
 	if (test_cfgfile_empty_file())
 		return -1;
 
-- 
2.12.1